Recent UFC light-heavyweight title challenger Chael Sonnen is still pushing for a fight with Wanderlei Silva – and he’s given the Brazilian a 24-hour deadline to give the green light.

“Wand- you have 24 hours to accept,” Sonnen tweeted Wednesday night. “If you do, I will donate 10% of my purse to help schools in your hometown of Curitiba .. I mean, VEGAS.”

Sonnen (27-13-1 MMA, 6-6 UFC), who previously said he chose Silva (35-12-1 MMA, 5-7 UFC) because he wants “an easy fight” and because “Wanderlei is broke,” began campaigning for the matchup soon after his April 27 title loss to Jon Jones. The bout marked the former top middleweight contender’s return to the division, where he competed early in his career.

With both fighters far from a title shot, it’s a marketable option with two proven names. The bout, in fact, is a possibility for the debut UFC on FOX Sports 1 card in Boston on Aug. 17.

Silva, who had been competing at middleweight and in catchweight fights, most recently fought in March, when he moved up to 205 pounds and scored a rousing knockout win over Brian Stann in UFC on FUEL TV 8’s headliner. It marked his second win in three fights, which also included a TKO victory over former Strikeforce champion Cung Le.